July 2023

SUMMARY OF THE METEOROLOGICAL READINGS AT DURHAM UNIVERSITY OBSERVATORY

July 2023

Temperatures (all temperatures in degrees Celsuis; all averages 1991-2020)

Mean daily maximum: 19.6   Difference from average: -0.6

Mean daily minimum: 11.8    Difference from average: +0.5

Mean air temperature: 15.7    Difference from average: -0.1

Absolute maximum: 27.8 (8^th)

Absolute minimum: 8.9 (4^th)

Mean grass minimum: 10.5    Difference from average: +1.0

Absolute grass minimum: 6.6 (20^th)

Mean concrete minimum: 11.8

Absolute concrete minimum: 8.3 (4^th)

Number of ground frosts: 0    Difference from average: 0

Number of air frosts: 0           Difference from average: 0

Mean soil temperature at 300 mm depth: 17.1

Mean soil temperature at 1000 mm depth: 15.7

Rainfall (all totals in millimetres; all averages 1991-2020)

Total for the month: 113.6      Difference from average: +51.6

Percentage of the average: 183%

Wettest day: 17.6 (22^nd)

Number of rain days (>0.1 mm): 24   Difference from average: +9

Number of wet days (=>1.0 mm): 16

3-month total rainfall to 31^st July 2023: 191.8             Difference from average: +24.1

6-month total rainfall to 31^st July 2023: 314.2             Difference from average: +8.7

12-month total rainfall to 31^st July 2023: 716.6           Difference from average: +35.6

Sunshine (all totals in hours; all averages 1991-2020)

Total for the month: 148.9                  Difference from average: -26.3

Percentage of the average:  85%

Mean daily sunshine:  5.0      Difference from average: -0.7

Sunniest day: 7.2 (7^th)

Number of days with no recorded sunshine: 0

Note that the monthly sunshine total is now calculated from the UKMO E&NE regional total. Daily sunshine totals quoted here and in the data summary are uncorrected.

Wind (kph; all data from the West Building roof, Lower Mountjoy campus)

 

Average wind speed: 2.7

Maximum gust: 61.2 (1^st, 12:30, W)

Comments on July 2023

This was the first month with below-average mean air temperature this year. Nights were warmer than average, but days were disappointingly cool, with only 2 days above 25 C° (which is the average number for the month, but nevertheless a disappointing total).  The weather was doubly disappointing given how hot the previous two Julys have been. It was the 13^th wettest July since 1850, with 24 rain days. As expected, sunshine was below average, but not excessively so, the 50^th dullest July since 1882.

Emeritus Professor Tim Burt

Department of Geography

Durham University

[email protected]